Diagnostic preparation for detection of helicobacter pylori

Abstract

PCT No. PCT / SE95 / 01212 Sec. 371 Date May 29, 1997 Sec. 102(e) Date May 29, 1997 PCT Filed Oct. 17, 1995 PCT Pub. No. WO96 / 14091 PCT Pub. Date May 17, 1996A preparation for administering isotope-labelled urea together with acid in a solid form that is influenced by activity of Helicobacter pylori in the stomach only, avoiding any non-Helicobacter (unspecific) urease activity in the oral cavity and the pharynx. The preparation dissolves very quickly in the stomach. The preparation is used to show increased urease activity in the stomach in association with an ongoing Helicobacter pylori infection.

Description

This application is a 371 of PCT / SE95 / 01212, filed Oct. 17, 1995.Diseases relating to gastric ulcers, are a serious public health problem and cost the community large sums of money in the form of medical costs and lost working ability. It has been fully established that the presence of Helicobacter pylori in the stomach is a necessary prerequisite for the development of stomach ulcers and / or duodenal ulcers. If the bacterium is not present in the stomach, no ulcer will develop. It has also been established that when a Helicobacter pylori infection is cured with the aid of antibiotics, there will be no relapse in stomach ulcer diseases. Stomach ulcer diseases are therefore considered to be bacterium-caused diseases which can and shall be cured.There is a great need for a reliable and simple diagnosis in this regard, as large patient populations inflicted with gastrointestinal problems will need to be examined with regard to the presence of a Helicobacter pylori infection.The present ...

AI Technical Summary

Benefits of technology

By constructing a capsule, tablet or some other solid preparation that has a high rate of disintegration and contains isotope-labelled (.sup.11 C, .sup.13 C, .sup.14 C) urea in combination with an acid, the following four important advantages are obtained with urea-breath tests relating to the diagnosis of gastric ulcer diseases:

1. When isotope-labelled urea is administered in the form of a solid preparation, the degradation by urease-producing bacteria in the oral cavity and the pharynx before the urea has reached the stomach is prevented. This reduces the number of falsely positive results and therewith significantly increases the reliability of the examination.

2. The administration of a weak acid at the same time as the isotope-labelled urea is administered also enables the urea-breath test to be performed during ongoing acid-suppression inhibiting treatment. This is a significant gain, since the majority of the patients who are subjected to the urea-breath test are chronically treated with potent acid-secretion inhibiting drugs. This substantially reduces the occurrence of falsely negative results.

3. Because isotope-labelled urea and a weak acid in capsule, tablet or other solid form, are stable over a relatively long period of time, the problems caused by the limited chemical stability of urea in aqueous solution are avoided.

This affords significant practical advantages with regard to distribution and application of the urea-breath test.

4. The use of a ready-prepared solid preparation (e.g. a tablet) also affords advantages with regard to dosage accuracy and time saving, in comparison with preparing the established water-based test liquid.

Problems solved by technology

Diseases relating to gastric ulcers, are a serious public health problem and cost the community large sums of money in the form of medical costs and lost working ability.

This examination is both expensive and unpleasant to the patient.

One drawback with these methods is that it is necessary to take blood samples or secretion from the stomach.

After successful treatment of the bacterial infection, elevated contents of antibodies remain in the blood for a very long time, thereby greatly limiting the possibility of accurately checking the condition of treated patients.

Furthermore, because the urea supplied to the patient disperses over the whole surface of the stomach, the fact that the bacterium has a very spotty distribution area lacks significance.

1. Isotope-labelled urea is ingested as an aqueous solution. This means that the urea can be broken down by urease-producing bacteria in the oral cavity and the pharynx of the patient, which may result in falsely positive indications regarding the presence of Helicobacter pylori.

2. In order for the test to be successful, it is necessary for a given quantity of hydrogen ions to be present in the stomach in order for the bicarbonate formed to be converted into carbon dioxide. Many patients who suffer from stomach ulcers are treated with an acid-suppression inhibitors which gives a falsely negative test result when such patients are diagnosed in accordance with present methodology.

3. Isotope-labelled urea has only a short chemical durability in aqueous solution, which causes practical difficulties when the patient is tested clinically.

It will be evident from the foregoing that several diagnostic methods of showing the presence of Helicobacter pylori in the stomach are known to the art, but that these methods are encumbered with a number of disadvantages, for instance are deficient in positively showing the presence of bacteria or are unpleasant for the patient.